The present invention relates generally to oiling systems for internal combustion engines, and more specifically, to a manifold for distributing engine oil in a two-stroke internal combustion engine.
Typically, two-stroke outboard marine engines did not have a separate oiling system. That is, these prior art engines required pre-mixing lubricant and fuel so that the lubricant dissolves in the fuel to lubricate the engine. This required consistent, accurate measuring and agitation of the mixture. There are many disadvantages to the prior art system of pre-mixing lubricant and fuel. For example, since various two-stroke engines require different mix concentrations, many outboard marine engine owners who also own other two-stroke engine equipment, such as various lawn and garden equipment and ATV""s, may store several different concentrations of oil/fuel mixture. This is not only an aggravation to the owner, but is also problematic if the containers become mixed up and the owner uses the wrong concentration for a particular two-stroke engine. While this is not catastrophic, if run over time with the wrong concentration, a two-stroke engine wears excessively.
The present invention is for use in a unique lubrication system for two-stroke engines. Such a lubrication system must not only provide lubrication to each cylinder of the engine, it must also provide lubrication to the fuel system to properly lubricate the fuel metering and injection system. As is well known, air entrained in the oil, can hinder a properly operating lubrication system. It is therefore desirable to remove any air from the oil, while preventing any such air in the oil system from being fed to the cylinders of the engine. As is known, air in such a system can prevent oil flow, especially where check valves are used, resulting in a phenomena known as xe2x80x9cair lock.xe2x80x9d If an oil passage becomes air locked, the operator would have no way of knowing that the affected cylinder is not receiving sufficient oil, and continued operation of the engine will result in severe damage to that particular cylinder.
It would therefore be desirable to have a distribution manifold that can evenly distribute oil to a number of cylinders of an internal combustion engine and purge air from the oil system while providing oil to the fuel system components. It would also be advantageous to be able to use a single distribution manifold with engines of differing number of cylinders.
The present invention provides a distribution manifold for distributing engine oil to each cylinder of an internal combustion engine and to the fuel system as well as purges air from the oil system. The present invention also provides a design for a distribution manifold capable of being used with either a four cylinder or six cylinder internal combustion engine. Further, the present invention provides an oiling system for a two-stroke outboard marine engine utilizing a manifold as disclosed herein, as well as, a solenoid mounted to an oil system housing to control engine oil flow to the distribution manifold. All of which overcome the aforementioned drawbacks.
In accordance with one aspect of the invention, a distribution manifold for use with a two-stroke internal combustion engine is provided. The distribution manifold includes a number of cylinder oiling outlets to provide oil to each cylinder of the two-stroke internal combustion engine. The manifold also includes a fuel system oiling outlet extending from a centrally-located dome at a height axially above the other outlet housings and is in fluid communication to provide regulated oil flow to the fuel system. A notch extends along a upper portion of the interior surface of the centrally-located dome to purge air from the oil system through the fuel system.
Another aspect of the present invention is to provide a distribution manifold having a centrally-located chamber. The centrally-located chamber has a plurality of cylinder outlet ports and a fuel system outlet port. The fuel system outlet port is positioned at an elevation higher than the cylinder outlet ports. Positioning of the fuel system outlet port at an elevation higher than the cylinder outlet port allows air trapped in the centrally-located chamber to rise to the top of the chamber to be purged through the fuel system downstream.
It is yet another aspect of the invention, to provide a design for an oil distribution manifold that may be utilized with a four cylinder as well as a six cylinder internal combustion engine. In the six cylinder configuration, the intake manifold has six cylinder outlet ports and a separate fuel system outlet port. The oil cylinder outlet ports each include an oiling outlet valve that regulates the flow of pressurized engine oil to each of the cylinders. To accommodate a four cylinder internal combustion engine two oiling outlet valves are removed from two of the cylinder outlet housings to prevent the flow of oil to the engine cylinders. Removing the two oiling outlet valves fluidly isolates these housings from the centrally-located chamber.
It is still a further object of the present invention to provide an oiling system for a two-stroke outboard marine engine. The oil system has a housing having an oil inlet and an oil outlet. A distribution manifold is mounted to the housing and is in fluid communication with the oil outlet of the housing. The manifold has a plurality of cylinder oiling outlets as well as a fuel system oiling outlet. A solenoid is also mounted to the oil system housing to control the flow of engine oil from the oil pump to the manifold and to each cylinder of the fuel system of the internal combustion engine.
The invention also includes a method of using an oil distribution manifold in engines having differing number of cylinders. The method includes molding a distribution manifold with N cylinder oiling outlet housings and a centrally-located oil chamber. A number of passages are molded into the cylinder oiling outlet housings to communicate with the centrally-located oil chamber. The number of passages is equal to N if a number of cylinders of an engine is equal to N, and the number of passages is equal to M if the number of cylinders is equal to M, where M is less than N. In this manner, the same basic structure of the manifold can be used for engines having different number of cylinders.
The invention also includes a method of bleeding air from an oil system of an internal combustion engine that includes providing an oil outlet port for each cylinder of an engine and an oil outlet port for a fuel system of the engine, and positioning the outlet port for the fuel system at a higher elevation than each of the oil outlet ports for each cylinder. The outlet port for the fuel system is connected to a fuel separator in the fuel system. Thus, air in the oil system is allowed to bleed through the outlet port for the fuel system and is purged through the fuel separator, thereby removing air from the oil system.
Various other features, objects and advantages of the present invention will be made apparent from the following detailed description and the drawings.